A growing number of portable user communication devices, such as laptops, tablets, smart phones, and feature phones, support multiple wireless technologies, such as WIFI, WIMAX and Cellular Wireless Technologies (GSM/SPRS, Edge, HSPA, LTE, CDMA). Within the cellular wireless technology, also known as the Radio Access Network (RAN), provided by a wireless cell operator, there could be multiple technologies, such as GSM/GPRS, Edge, HSPA, LTE, 1XRTT, EVDO and others. Standard protocols (such as 3GPP, 3GPP2) define control protocols by which the user device selects a component access technology with the same class of RAN (for example GSM/GPRS, Edge, HSPA, or LTE) based on the signal strength seen by the user device and Public Land Mobile Network (PLMN) type. The service is initiated by the user in co-ordination with the Base Station and Radio Network Controller. However wireless LAN technologies, such as WIFI and WiMAX, originally developed for enterprise and private networks, are becoming increasingly available as WIFI hotspots in several areas, such as airports, event stadiums, shopping malls and other venues. These services may be offered by the same operator as the wireless cell operator or by a different operator. Also, cell operators are deploying micro and femto cells in certain locations to increase the capacity and coverage in dense locations.
As mentioned above, the network selection in the majority of the mobile wireless devices is based on Received Signal Strength or based on the configuration of the best network in the device, and by type of service (voice or data), that the user initiates. For example, on a UMTS device, that has connectivity to both UMTS and WIFI networks, when the user initiates a circuit switched (CS) service, such as a voice call or SMS, the device uses the UMTS RAN. When the user initiates packet switched (PS) services, the device uses WLAN. If the device is currently not associated with a WIFI access point (AP), and if the WIFI radio is enabled, the device attempts to connect to the highest priority WLAN/SSID that it successfully connected to previously. The load on the WLAN or the UMTS RAN, whether the user device is in high mobility environment, and the type of content or resource needs of the user application are not factored into the access network selection. Thus, with the above methods, when a number of users enter the vicinity of a WIFI AP, and the users are authorized to use the WLAN, all the user devices connect to and start using the WLAN for packet services thus causing congestion on that particular WLAN. Additionally, if the user is mobile and moving in and out of WIFI-AP coverage area, his service keeps oscillating between WLAN and RAN for packet services.
3GPP standards define Access Network Discovery and Selection (ANDSF) methods by which a mobile device identifies which access network to connect to (Network Selection and Inter System Mobility Policy), or which network to route specific IP flows to (Inter System Routing Policy). This framework uses a client application (ANDSF Client) and server (ANDSF Server) in the operator's core network. The ANDSF Server may be a new device in the operator network or its function may be incorporated into an existing core network (CN) device, such as the PCRF. The ANDSF server communicates priorities for one or more access networks or for forwarding selective IP flows to the ANDSF Client in user device. The client's connection to the ANDSF Server may be client initiated (client pull) or initiated using Network Push through mechanisms, such as SMS. The network policy propagated by the ANDSF server could indicate that in a specific location (such as particular RAN sector ID or geo location), a specific WLAN has a higher priority. Thus, a client application could turn on the WIFI radio when it enters the coverage area of a sector. The standards do not specify how the ANDSF server prioritizes the access networks for a user, or a dynamic mechanism that the ANDSF server should use based on congestion, network state or user access patterns of the access networks.
Thus, an improved system and method for selecting an appropriate network for a user device, based on criteria, such as mobility, congestion, and usage pattern, would be beneficial.